Question For The Thinkers

[SHOOTALL]

if you were 3moa off in 12 inches , you would be looking at the front blade around the side of the rear sight !
When i shot my XP-100 7br. in competition , at 100 yards we had groups in the 1-11/2 inch range all day long our sight radius was near 121/2 inches to 131/2 inches ( my front sight hole was buggered up ) to open up to 3 inches ( inches not moa  but a reasonable measure ) it could take little more than a cloud to come over change the light ! or in my case a few years to change the eye !
sorry i don't have the moa vs. inch formula but degrees ain't inches !

[MePlat]

SHOOTALL:  Please tell me what the numerical value is for 3MOA on a 12 inch sight radius?  I would be very interested in your answer.  If you don't know at least be honest about it and say.  Maybe take a stab at it okay.

[SHOOTALL]

that was a joke , MOA as related to firearms most often at 100 yards is the spread of bullets fired at the target .
fire two bullets if center to center the spread is 1 inch most say it is a 1 MOA rifle , not exact but accepted .
some would ask what the revolver 's moa was then multiply by 3 or some may add the guns moa to the 3 moa error . To be honest i don't see a way to really answer his ? with what is stated !

line of sight is straight , bullets fly in arcs some more than others !
Moa is what happens at the target with the bullet(s) ! often a sighting point is chosen and shots are fired and measured with out regard to accy . related to the sights !

hope i passed your test , what i get for making a joke !

[MePlat]

SHOOTALL:     It was a joke alright.  You really don't know do you?  When a straight line deviates from straight on one end it is measured in degrees minutes and seconds be cause it then creates an angle.  you do get it don't you?

What is the angle of 1.0472" at 100 yards?  What is the numerical value of 1 moa at 100 yards?

Do you have the answer?

[SHOOTALL]

do you have a gun that shoots STRAIGHT lines ( bullet paths ) ? I don't !

[MePlat]

My question is not about the bullet path but the line of sight and the error in IT .  I know bullets diverge from straight to the target that is how a group is built but the line of sight is straight even if it has some error in alignment it is straight in its line to the target it doesn't curve here and there along it path.
How about sticking to the question I asked and not one of yours that you decide to answer.

Now answer this question:  What is the angle of 1.0472" at 100 yards?  What is the numerical value of 1 moa at 100 yards?

[ncsurveyor]

An angle of 1 minute subtends 1.0472" at 100 yards.

next question.

[SHOOTALL]

what the heck !
if you shoot your rifle at a target 5 times and all shots stay in a 1 in. circle you have a 1 moa rifle by most peoples standard ! yes bench rest shooters get more tech.
1/60 of a degree !
1.047197580733 inch

[SHOOTALL]

I was contacted by one of the posters and felt i should go back and read , if we forget moa and put in degrees it seems to make sense !
the length of the bbl doesn't make a gun inaccurate , the sight radius does not either . however the sight radius on a longer gun gives more to look at and less chance to be off . what you see !
i offer this , i once owned a mod-66 S&W that back in my day it shot very accurate , but you really had to have a good sight picture to hit with it , the front sight on a 21/2 in. bbl was close to the rear sight so a small amount of miss alignment would show up big down range , now on my 10 in. bbl ruger you could get quite sloppy with aiming and still stay on target !
if both guns had been shot in a vise my money would have been on the m-66 .
we blame sights and bbl length when i believe it has as much to do with our eyes as anything ! we called it seeing more light on one side the front post OR letting the front post sit low or high in the rear sight !
easiest way to check is put a scope on a short bbl gun and a long bbl. gun and shoot them ! bbl length ain't the cause most the time .

[deltecs]

What meplat is saying is if one took a perfectly straight string exactly on the center line of a pistol bore to a point on a target and marked the target.  Then taking the same string and moving it at the target end so that all points make a circle with an error of 3 MOA from the straight line target mark with angle at the rear sight.  If one could mark the string in increments of 1" along it, then from the rear sight all marking along the string would be in error at 3 MOA.  So with markings at 6", 12", 36", or 99 yard barrels, the same radian error is encountered, exactly 3 MOA.  Graybeards immediate post is exactly correct. It has nothing to do with trajectory, sight picture, or barrel length.  The question is rhetorical at best.  One posted that because he could hold a 3 MOA sight picture with a 6" pistol and 3 MOA with a 12" barrel that this is reason to question the validity of shooting better with longer barrels.  Meplats question had nothing to do with bullet point of impact.  Personally I don't care what the MOA error is, I do care what the target impact is and may then determine my ability in MOA.  I would love to be able to shoot 3 MOA at 100 yards with a handgun.  I have enough trouble consistently shooting 3 MOA with a rifle using telescope sights.  So who cares what the MOA is before the bullet hits the target.

[SHOOTALL]

Some front sights block more than 3 inches at 100 yds !

[Questor]

The sight radius has nothing to do with MOA. It has to do with your ability to perceive a good sight picture.

[S.B.]

3 MOA is 3 MOA, no matter what barrel length, no matter what the sight radius is, until you interject the distance it's being shot, in this equation. MOA deals with where the bullet strikes the target, not where the sights are when the gun is shot.

[MePlat]

A 3 MOA sight misalignment continues all the way to the target no matter how far away the target is.

[S.B.]

But is measured by the equation of distance to target. You can't logically figure this without the distance in the calculations.

[MePlat]

Pick your target distance 25?, 50?, 100?, etc.  3 MOA is 3 MOA   This is a fact that is supported mathematically and cannot be argued no matter how much one tries to conjer up enough black magic to use as a leverage point.

[MS Hitman]

I will frame my response to this question with the following two definitions as provided by Wikipedia.com and “The Complete Book of Hunting” by Robert Elman, respectively:

1)   A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60) of one degree.
2)   Sight radius: The distance between the front and rear sights.

For simplicity sake, all angles as I discuss them will be considered from the line of sight to the full angular measurement below the line.  This eliminates dividing, the measurements in half and having to state the usual plus or minus or above and below the line of sight.

The original question, posed poorly at best, appears to be an attempt to stir the pot from the application of a little knowledge.

As has been previously stated, minute of angle has nothing whatsoever to do with sight radius.  I refer to the previously provided definition. 

MePlat has stated the following, “3 MOA is a fixed measurement.  .0105 ".  This is the distance subtended by 3 MOA at 1 foot and 1 foot only.  He further states the following in a later post “Pick your target distance 25?, 50?, 100?, etc.  3 MOA is 3 MOA”.  I will agree that 3 MOA is 3 MOA, regardless of target distance; however and again, I refer to the above definition. 3 MOA subtended at 25 yards is not equal to 3 MOA subtended at 100 yards.  In fact, 3 MOA subtended for 25, 50, 75, and 100 yards are 0.7854”, 1.5708”, 2.3562”, and 3.1416” respectively.  I am holding my calculations to four significant figures as anything past one ten thousandth of an inch is unnecessary. 

Discounting all other variables than sight alignment, or misalignment as the case may be, shooting 3 MOA or less at 100 yards with a firearm having a sight radius of 12” requires the sights be held within a misalignment of 0.0105” or less.  Reduce the sight radius to 6” and the misalignment must be held to within 0.0052” or less for the same distance.  Further reduction of the sight radius to 4” requires the misalignment be held to 0.0035” or less for the same distance. To use MePlat’s own words, “This is a fact that is supported mathematically and cannot be argued no matter how much one tries to conjer up enough black magic to use as a leverage point.”

As I stated earlier, because the question was so poorly worded; I will address the other side of the coin so to speak.  A sight misalignment of 0.0105” on a firearm with a 12” sight radius will result in a 3 MOA difference between point of aim (POA) and the point of impact (POI) at 100 yards.  Again, this is eliminating all other variables influencing bullet flight.  A sight misalignment of 0.0105” on a firearm with a 6” sight radius would result in a POA/POI difference of 6.3” or approximately 6 MOA and the same sight misalignment for a firearm with a 4” sight radius would result in a POA/POI difference of 9.45” or approximately 9 MOA at 100 yards as well.

Although it may or may not be used as an excuse, the above shows a longer sight radius is more "forgiving" for slight misalignment of the sights at the time a bullet is fired. 

[MePlat]

  MS HITMANl lets see if I can answer these statements from someone that is more intelligent than me since I am of the television.

"As has been previously stated, minute of angle has nothing whatsoever to do with sight radius.  I refer to the previously provided definition"

MOA does have something to do with sight radius:  Lets see.  If we misalign the sights on a 12 inch sight radius .0105"  we can figure the moa of that misalignment.
Example :  12 x 2 = 24  24 X 3.14159 = 75.3981"  / 21600 =.0035"  (1 MOA)  .0035 x 3 =.0105"  3 MOA.  that means our sight misalignment from true alignment is 3 MOA off.  Where does that not fit in Hitman?

"Discounting all other variables than sight alignment, or misalignment as the case may be, shooting 3 MOA or less at 100 yards with a firearm having a sight radius of 12” requires the sights be held within a misalignment of 0.0105” or less.  Reduce the sight radius to 6” and the misalignment must be held to within 0.0052” or less for the same distance.  Further reduction of the sight radius to 4” requires the misalignment be held to 0.0035” or less for the same distance. To use MePlat’s own words, “This is a fact that is supported mathematically and cannot be argued no matter how much one tries to conjer up enough black magic to use as a leverage point.”

If we reduce the sight radius to 6 inches we will see that the misalignment is still 3 MOA althought the numerical measurment is less it is still 3 MOA 
Example.  6 x 2 = 12  12 X 3.14159 =37.6991"  37.6991 / 21600 = .00175  1 MOA  .00175 X 3 =.00525"  3 MOA which is half the numerical value of the .0105 misalignment of the 12 inch radius but it is still 3 MOA misalignment anyway you cut it., disect it or conjer over it.

"Discounting all other variables than sight alignment, or misalignment as the case may be, shooting 3 MOA or less at 100 yards with a firearm having a sight radius of 12” requires the sights be held within a misalignment of 0.0105” or less.  Reduce the sight radius to 6” and the misalignment must be held to within 0.0052” or less for the same distance.  Further reduction of the sight radius to 4” requires the misalignment be held to 0.0035” or less for the same distance. To use MePlat’s own words, “This is a fact that is supported mathematically and cannot be argued no matter how much one tries to conjer up enough black magic to use as a leverage point.”

That is correct Hitman. But if you can hold steady enough to hold a given MOA error in your aiming with a 12 than  how would the MOA error of a 6 inch radius mysteriously go all to pot when one is holding 3 moa with the 12 inch radius.  Remember that by your own figures and backed up by me says that the numerical  misalignment on the 6 inch would only be half of the numerical misaligment 12 inch radius not more as some would believe.  But still the same MOA misalignment.

"As I stated earlier, because the question was so poorly worded; I will address the other side of the coin so to speak.  A sight misalignment of 0.0105” on a firearm with a 12” sight radius will result in a 3 MOA difference between point of aim (POA) and the point of impact (POI) at 100 yards.  Again, this is eliminating all other variables influencing bullet flight.  A sight misalignment of 0.0105” on a firearm with a 6” sight radius would result in a POA/POI difference of 6.3” or approximately 6 MOA and the same sight misalignment for a firearm with a 4” sight radius would result in a POA/POI difference of 9.45” or approximately 9 MOA at 100 yards as well.

You are comparing apples to oranges here now. As I am sure you know that misalignment of .0105 numerical value on a 12 inch radius is 3 MOA but the same numerical misalignment on a 6 inch radius is 6 MOA not 3 MOA.
But the reverse is true if you can hold a 6 MOA error on a 6 inch radius you can hold 6 MOA on a 12 inch radius.
Now tell me how that one can hold a given steadiness with a 12 inch radius and that hold with a 6 inch radius can go down the toilet immediately?  Is it really the sight radius or is it all in the mind?  How can ones steadiness just disappear because of a change in the physical properties of the sight radius?  Is not the steadiness in ourselves?

[SHOOTALL]

what a waste of space !

[Graybeard]

Clearly the OP hasn't a clue and is only wanting to stir the pot with this by continuing it. This one is now closed and locked.